1. Field of the Invention
The present invention relates to a heat dissipating device, and particularly to a heat dissipating device which is attached to an electronic package to remove heat therefrom.
2. Prior Art
Electronic devices such as central processing units (CPUs) generate a lot of heat during normal operation. This can deteriorate their operational stability and damage associated electronic devices. Thus the heat must be removed quickly to ensure normal operation.
FIG. 4 shows a conventional heat dissipation device 20. The heat dissipation device 20 comprises a flat base 220 a plurality of fins 240 extending from the base 220 and a fan 260 mounted on the fins 240. During operation of the heat dissipation device 20, the fan 260 draws ambient cooling air to the heat dissipation device 20. The air flows down in channels defined between the fins 240 for heat exchange with the fins 240. When the air arrives at the base 220, some of it simply refluxes instead of exiting from the channel. When the refluxed air meets downward flowing air, the downward flowing air is prevented. Thus an overall speed and efficiency of cooling airflow is retarded. This can seriously affect the heat dissipation capability of the heat dissipation device.
FIG. 5 shows an improved heat dissipation device. The heat sink includes a base 120 and a plurality of fins 14. The base 120 has a first surface in thermal contact with an electronic package arid a pair of sloped beat dissipation surfaces. The fins 14 are perpendicularly attached on the heat dissipation surfaces. The fan 30 is supported on the heat sink. During operation of the heat dissipation device, the cooling air is drawn into the heat sink by the fan 30 and exits the heat sink along the heat dissipation surface. However, this improved heat dissipation device has complex structure. It is not adapted to mass manufacture.